timer: Add a test for timer_timebase_fallback

To test this function, sandbox CPU must set cpu_platdata.timebase_freq on
bind. It also needs to expose a method to set the current cpu. I also make
some most members of cpu_sandbox_ops static.

On the timer side, the device tree property
sandbox,timebase-frequency-fallback controls whether sandbox_timer_probe
falls back to time_timebase_fallback or to SANDBOX_TIMER_RATE.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

5 files changed, 80 insertions, 10 deletions

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 9f45c48e4e..2f559265a5 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -533,7 +533,9 @@
 	};
 
 	cpus {
+		timebase-frequency = <2000000>;
 		cpu-test1 {
+			timebase-frequency = <3000000>;
 			compatible = "sandbox,cpu_sandbox";
 			u-boot,dm-pre-reloc;
 		};
@@ -839,11 +841,16 @@
 			0x58 8>;
 	};
 
-	timer {
+	timer@0 {
 		compatible = "sandbox,timer";
 		clock-frequency = <1000000>;
 	};
 
+	timer@1 {
+		compatible = "sandbox,timer";
+		sandbox,timebase-frequency-fallback;
+	};
+
 	tpm2 {
 		compatible = "sandbox,tpm2";
 	};
diff --git a/arch/sandbox/include/asm/cpu.h b/arch/sandbox/include/asm/cpu.h
new file mode 100644
index 0000000000..c97ac7ba95
--- /dev/null
+++ b/arch/sandbox/include/asm/cpu.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ */
+
+#ifndef __SANDBOX_CPU_H
+#define __SANDBOX_CPU_H
+
+void cpu_sandbox_set_current(const char *name);
+
+#endif /* __SANDBOX_CPU_H */
diff --git a/drivers/cpu/cpu_sandbox.c b/drivers/cpu/cpu_sandbox.c
index caa26e50f2..4ba0d1b99e 100644
--- a/drivers/cpu/cpu_sandbox.c
+++ b/drivers/cpu/cpu_sandbox.c
@@ -8,14 +8,15 @@
 #include <dm.h>
 #include <cpu.h>
 
-int cpu_sandbox_get_desc(const struct udevice *dev, char *buf, int size)
+static int cpu_sandbox_get_desc(const struct udevice *dev, char *buf, int size)
 {
 	snprintf(buf, size, "LEG Inc. SuperMegaUltraTurbo CPU No. 1");
 
 	return 0;
 }
 
-int cpu_sandbox_get_info(const struct udevice *dev, struct cpu_info *info)
+static int cpu_sandbox_get_info(const struct udevice *dev,
+				struct cpu_info *info)
 {
 	info->cpu_freq = 42 * 42 * 42 * 42 * 42;
 	info->features = 0x42424242;
@@ -24,21 +25,29 @@ int cpu_sandbox_get_info(const struct udevice *dev, struct cpu_info *info)
 	return 0;
 }
 
-int cpu_sandbox_get_count(const struct udevice *dev)
+static int cpu_sandbox_get_count(const struct udevice *dev)
 {
 	return 42;
 }
 
-int cpu_sandbox_get_vendor(const struct udevice *dev, char *buf, int size)
+static int cpu_sandbox_get_vendor(const struct udevice *dev, char *buf,
+				  int size)
 {
 	snprintf(buf, size, "Languid Example Garbage Inc.");
 
 	return 0;
 }
 
-int cpu_sandbox_is_current(struct udevice *dev)
+static const char *cpu_current = "cpu-test1";
+
+void cpu_sandbox_set_current(const char *name)
 {
-	if (!strcmp(dev->name, "cpu-test1"))
+	cpu_current = name;
+}
+
+static int cpu_sandbox_is_current(struct udevice *dev)
+{
+	if (!strcmp(dev->name, cpu_current))
 		return 1;
 
 	return 0;
@@ -52,7 +61,22 @@ static const struct cpu_ops cpu_sandbox_ops = {
 	.is_current = cpu_sandbox_is_current,
 };
 
-int cpu_sandbox_probe(struct udevice *dev)
+static int cpu_sandbox_bind(struct udevice *dev)
+{
+	int ret;
+	struct cpu_platdata *plat = dev_get_parent_platdata(dev);
+
+	/* first examine the property in current cpu node */
+	ret = dev_read_u32(dev, "timebase-frequency", &plat->timebase_freq);
+	/* if not found, then look at the parent /cpus node */
+	if (ret)
+		ret = dev_read_u32(dev->parent, "timebase-frequency",
+				   &plat->timebase_freq);
+
+	return ret;
+}
+
+static int cpu_sandbox_probe(struct udevice *dev)
 {
 	return 0;
 }
@@ -67,5 +91,6 @@ U_BOOT_DRIVER(cpu_sandbox) = {
 	.id             = UCLASS_CPU,
 	.ops		= &cpu_sandbox_ops,
 	.of_match       = cpu_sandbox_ids,
+	.bind		= cpu_sandbox_bind,
 	.probe          = cpu_sandbox_probe,
 };
diff --git a/drivers/timer/sandbox_timer.c b/drivers/timer/sandbox_timer.c
index 5228486082..6a503c2f15 100644
--- a/drivers/timer/sandbox_timer.c
+++ b/drivers/timer/sandbox_timer.c
@@ -40,7 +40,9 @@ static int sandbox_timer_probe(struct udevice *dev)
 {
 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 
-	if (!uc_priv->clock_rate)
+	if (dev_read_bool(dev, "sandbox,timebase-frequency-fallback"))
+		return timer_timebase_fallback(dev);
+	else if (!uc_priv->clock_rate)
 		uc_priv->clock_rate = SANDBOX_TIMER_RATE;
 
 	return 0;
diff --git a/test/dm/timer.c b/test/dm/timer.c
index 95dab97665..70043b9eee 100644
--- a/test/dm/timer.c
+++ b/test/dm/timer.c
@@ -7,8 +7,10 @@
 #include <dm.h>
 #include <timer.h>
 #include <dm/test.h>
+#include <dm/device-internal.h>
 #include <test/test.h>
 #include <test/ut.h>
+#include <asm/cpu.h>
 
 /*
  * Basic test of the timer uclass.
@@ -17,9 +19,32 @@ static int dm_test_timer_base(struct unit_test_state *uts)
 {
 	struct udevice *dev;
 
-	ut_assertok(uclass_get_device(UCLASS_TIMER, 0, &dev));
+	ut_assertok(uclass_get_device_by_name(UCLASS_TIMER, "timer@0", &dev));
 	ut_asserteq(1000000, timer_get_rate(dev));
 
 	return 0;
 }
 DM_TEST(dm_test_timer_base, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
+
+/*
+ * Test of timebase fallback
+ */
+static int dm_test_timer_timebase_fallback(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	cpu_sandbox_set_current("cpu-test1");
+	ut_assertok(uclass_get_device_by_name(UCLASS_TIMER, "timer@1", &dev));
+	ut_asserteq(3000000, timer_get_rate(dev));
+	ut_assertok(device_remove(dev, DM_REMOVE_NORMAL));
+
+	cpu_sandbox_set_current("cpu-test2");
+	ut_assertok(uclass_get_device_by_name(UCLASS_TIMER, "timer@1", &dev));
+	ut_asserteq(2000000, timer_get_rate(dev));
+
+	cpu_sandbox_set_current("cpu-test1");
+
+	return 0;
+}
+DM_TEST(dm_test_timer_timebase_fallback,
+	UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);